Carburetor and the like



Marchl 22, 1932. E. T. CHAMBERS CARBURETOR AND THE LIKE Filed July 3, 1929 f mL/mf el M gm@ Patented Mar. 22, 1932 UNITED STATES EDWARD THEODORE CHAMBERS, OF HOVE, ENGLAND CARBURETOR AND THE LIKE Application led July 3, 1929, Serial No. 375,713, and in Great Britain J'uly 3, 1928.

This invention relates to the production of mixtures of liquids and gases by the use of an inverted nozzle subjected to the depression caused by a flow of gas. It has already been proposed in such cases to use a knife edged capillary nozzle of annular or multiple form over which it was suggested a head of liquid exactly balancing' the capillary and surface tension effects should be maintained.

According to the present invention the head of liquid above a capillary nozzle is made less than that` required to balance the capillary and surface tension effects by a considerable margin. This ensures stabilityin I5 practical operation where variation in specific gravity, of the liquid vibratiomtilting, slight variations in thickness or level of the nozzle at different pointsand other unavoidable departures from ideal conditions cause excessive flow, and leakage when the apparatus is not in use.

According to a further feature of the invention, the delivery through the Capillary nozzle is controlled by a restriction in the liquid conduit above the nozzle, while the area of cross section of the nozzle is made larger than the 'area of the largest restriction it is intendedto use in a given apparatus. To enable the necessary head to be obtained, a small bore nozzle must be used and in general its cross section will be too small; I therefore providea series ofv nozzles, or preferably a nozzle of elongated section, for eX- amplean annular nozzle. The provision of a separate restriction for controlling delivery has the great practical advantage that the restriction can be changed without affecting the capillary nozzle and therewith the capillaryk head and therefore `without the need for delicate adjustments in level.

. The invention can be applied to any apparatus where mixtures of gas and liquid are require-d, for eXample blow lamps, and oil fuel vaporizers or atomizers, while its application to one preferred embodiment of carburetor for internal combustion engines is described in detail below, with reference to Figure 1 ofthe accompanying drawings in which Figure l shows the carburetor in lonlll) gitudinal section g, whileFigures 2 and 3 are detail views of the throttle valve.

The body l of the carburetor may advantageously be in one piece with the float chamber 2, the petrol level being maintained at 3 by any usual float and valve mechanism. A central fixed sleeve l projects upwards from the top of the chamber or Venturi passage 5 into the space 20 which communicates with the float chamber, being for example screwed in on to a packing washer 17. Within the sleeve 4 fits the nozzle which is preferably made up of two parts. The outer part comprises a sleeve 6 screwing into the sleeve 4 its walls at the lower end being made thin or sloped offV to a knifeedge as may be more convenient. A packing washer is provided at 18. The sleeves 4C and 6 can if desired be made in one piece. Into the sleeve 6 screws an inner member 7, drilled up a short distance from the bottom at 8 so as to leave a thin or sharp lower edge, a packing washer being provided at 19. The annular passage 9 thus formed is of capillary dimensions radially but its total area of cross section is greater' than a. constricted passage l0 which actually controls the flow and which is formed in a largerV passage 16. The radial dimension of the passage 9 and the shape of the lower edges of the members 6 and 7 is such that the head necessary to overcome the capillary and surface tension effects is considerably greater than the distance of the petrol level 3 above the lower edge of the nozzle.

The inner member 7 is shaped so that an annular passage 11 is formed by which the fuel coming through the passage 10 has access to the capillary passage all round, this passage l1 forming a fuel reserve which comes into action in the event of a sudden demand such as occurs when the throttle is rapidly opened.

Preferably the upperV edges of the sleeve 6 and inner member 7 are above the lever 3 and a siphon cap l2 is provided dipping below the level of petrol in the space 20 so that petrol cannot reach the nozzle until the engine suction causes the Siphon t0 ll. This arrangement is an added lprotection against leakage whenthe engine is not running.

A butterfly throttle 13 is pivoted in that of the nozzle axis.

portion ofV the venturior choke passage having the smallest effective cross sectional area, beneath the nozzle and advantageously with its spindle axis 14 slightly on the engine side The nozzle exit is some distance above the top of the passage 5 and the outlet is provided with a baile 15 open on the engine side only. .y l

' The construction of nozzle described enables the constricted passage 10 to be changed with ease and so long as the diameter of the lower part of the inner member 7 is the same, the capillary effect is unchanged. The lower diameter of the inner member mayhowever be changed to vary the capillary effect if y for fuel and one remote from the nozzle for the float chamber.

vsure above and below the valve in the air supair, for slowy running with the throttle closed.

Advantageouslyeither or both of these pasf sages kare adjustable. For this purpose* I provide a tapped *hole 22* cutting straight through the passage and into the hole fits a screw 23 provided with an annular groove 24-in its body. The groove is located so that kwhen the screw is screwed right in as deterv mined by engagement of its head or as shown its point 25 withfan abutment surface 26, the

f groove 24 is inposition to provide maximum flow. By screwing these screws out more or less the respective passages can be decreased and finallyV cut rightl off when the groove passes beyond the edge of thepassage.

In applying the invention to oil fuel vayporizers or atomizers, I use a similar arrangement to the carburetor shown in Figure 1, and Ik supply air thereto by means of a blower. To establish proper conditions of pressure and head, I employ a closed fuel tank and floatv chamber and provide pipes connecting air conduit `between the blowery and the throttle valve. y ,Y

In applying the invention to a blow lamp, the compressed air passing to the jet may pass through a valve of definite proportions'and weight and part of the air on the supply side of this valve may be led to The difference in presplyy pipe Visv thus available for exertion upon the liquid, butin accordance with the invention it mustbe less than the head due to the capillary and surface tension effects.

gin theliquid passage to form a liquid reservoir and having above said enlargement a restriction inthe liquid passage of less area than the area of cross section of said nozzle, said restriction being the sole entrance to Vsaid reservoir and said nozzle the sole outlet.

2. In apparatus for the production of mixtures of liquids and gases the combination of an inverted capillary nozzle and means forsupplying liquid to said nozzle under a positive head less than that required to balance the capillary and surface tension effects by a considerable margin, said means having immediately above said nozzle an enlargement iny the liquid passage to form a liquid reservoir and having abovesaidenlargement a. restriction lin the liquid passage of less area than thearea of cross section of said nozzle, said restriction being the sole entrance to `said reservoir and said nozzle the sole outlet.

3. In apparatus for theproduction of mixtures of liquids and gases the combination of an inverted nozzle, a bafiie below said nozzle projecting into the gas passage open on the rear side only and a throttle valve pivoted in the gas passage having its pivotal axis such a distance posterior to the laxis of the baflie that the axis of said baiiie intersects said throttle valve between the pivotal axis thereof and the anterior edge thereof. y

4. In apparatus for the production of mixtures of liquids and gases, the combination of an inverted capillary nozzle and a throttle valve pivoted in the gas passage having its pivotal axis such a distance posterior to the axis of the nozzle that the axis of said nozzle intersects said throttle valve between the pivotal axis thereof and the anterior edge into said throttle valve transversely through each of saidholes respectively. n

6. In apparatus for the production of mixtures of liquids and gases the combination of a thin walled outer nozzle member having a parallel bore and a separate thin walled inner nozzle'meniber` having a cylindrical portion of greater length than the bore of said f outer member, said inner member being mounted within said outer member with its end flush with the end of said outer member so that an annular capillary passage of constant-section leading from an annular reservoir is formed. f

7. In apparatus for the production of mixtures of liquids and gases the combination of an outer'nozzle member and an inner nozzle membermounted therein; said members being shaped tov leave a capillary passage between them and one of said members having a restricted passage therein of smaller area than the capillary passage and communicating therewith.. Y 'i 8'. In apparatus for the production of mixtures of liquids and gases, the combination of an outer nozzle member having a thin walled parallel sleeve at one end, and an inner nozzle member having a thin walled parallel sleeve at one end of greater length than the sleeve of said outer member, said inner member being mounted in said outer member so that the end of its sleeve stands flush with the end of the sleeve of said outer member and so that an annular capillary passage is formed leading from an annular reservoir, said inner member having a restricted passage of smaller area than that of the capillary passage formed in it communicating withy the reservoir.

9. In apparatus for the production of mixtures of liquids and gases, the combination of a horizontal choke tube, a transversely pivoted throttle valve in said choke tube at its smallest eii'ective area of cross section, and an inverted jet having its axis intersecting said throttle between its pivotal axis and its front edge.

l0. In apparatus for the production of mixtures of liquids and gases, the combination or a choke tube, a transversely pivoted throttle valve in said choke tube at its smallest effective area of cross section adapted to close by downward mot-ion of its front edge, a baflie projecting downwardly into said choke tube having an opening only on the rear side, and an inverted jet above said baille positioned f so that its axis intersects said throttle valve between its pivoted axis and its front edge.

ll. AIn apparatus for the production of mixtures of liquids and gases, the combination of an inverted capillary nozzle, means for maintaining a supply of liquid at a constant level, and a conduit leading from said constant level supply of liquid to said nozzle, said conduit having a restriction therein of smaller area than the cross section of said nozzle and having no inlets or outlets other than'said restriction and nozzle.

l2. In apparatus for the production of mixtures of liquids and gases, the combination of an inverted capillary nozzle, means 'or maintaining a supply of liquid at a constant level above said nozzle by an amount less than that required to balance the capillary and surface tension eii'ects by a considerable margin, and a conduit leading from said constant level supply of liquid to said nozzle, said conduit having a restriction therein of smaller area than the cross section of said nozzle and having no inlets or out-V lets other than said restriction and nozzle. In testimony whereof I have signed my name to this specification.

EDWARD THEODORE CHAMBERS. y 

